摘要:
A method for storing database information, including: storing a table having data values in a column major order, wherein the data values are stored in a list of blocks, assigning a tuple sequence number (TSN) to each data value in each column of the table according to a sequence order in the table, wherein data values that correspond to each other across a plurality of columns of the table have equivalent TSNs; assigning each data value to a partition based on a representation of the data value; and assigning a tuple map value to each data value, wherein the tuple map value identifies the partition in which each data value is located.
摘要:
A method for storing database information includes storing a table having data values in a column major order. The data values are stored in a list of blocks. The method also includes assigning a tuple sequence number (TSN) to each data value in each column of the table according to a sequence order in the table. The data values that correspond to each other across a plurality of columns of the table have equivalent TSNs. The method also includes assigning each data value to a partition based on a representation of the data value. The method also includes assigning a tuple map value to each data value. The tuple map value identifies the partition in which each data value is located.
摘要:
The present invention is directed towards a diagnostic system for a database system. The diagnostic system includes a grouping module for assigning a grouping identifier to each query received by the database system; and a statistics collection module. The statistics collection module includes a query processing statistics module for obtaining processing statistics corresponding to each query; a group statistics compilation module for compiling processing statistics for each query by the query's grouping identifier; and group data storage for storing compiled processing statistics. A method is also disclosed for generating database diagnostic data.
摘要:
A workload specification, detailing specific queries and a frequency of execution of each of the queries, and a set of partitions, are obtained for the database, as inputs. A number of candidate tables are identified for the database, the tables having a plurality of attributes. A chosen attribute is allocated for each of the tables, to obtain a set of tables and a set of appropriate partitions for each of the tables.
摘要:
In general, the disclosure is directed to techniques for choosing which pages to evict from the buffer pool to make room for caching additional pages in the context of a database table scan. A buffer pool is maintained in memory. A fraction of pages of a table to persist in the buffer pool are determined. A random number is generated as a decimal value of 0 to 1 for each page of the table cached in the buffer pool. If the random number generated for a page is less than the fraction, the page is persisted in the buffer pool. If the random number generated for a page is greater than the fraction, the page is included as a candidate for eviction from the buffer pool.
摘要:
Laboratory apparatus for performing repetitive tacks includes a table and first and second bearing ways below the table. First and second carriages are mounted on corresponding bearing ways for independent motion therealong, the second carrriage moving in a plane below and parallel to the first carriage. An independently operable transfer device moves objects between the table and a selected carriage or between the carriages, as desired, and apparatus is provided adjacent to the table for performing operations on objects located on the table or on the carriages, the transfer device, and the operating apparatus being capable of repetitive operation.
摘要:
A workload specification, detailing specific queries and a frequency of execution of each of the queries, and a set of partitions, are obtained for the database, as inputs. A number of candidate tables are identified for the database, the tables having a plurality of attributes. A chosen attribute is allocated for each of the tables, to obtain a set of tables and a set of appropriate partitions for each of the tables.
摘要:
A workload specification, detailing specific queries and a frequency of execution of each of the queries, and a set of partitions, are obtained for the database, as inputs. A number of candidate tables are identified for the database, the tables having a plurality of attributes. A chosen attribute is allocated for each of the tables, to obtain a set of tables and a set of appropriate partitions for each of the tables.
摘要:
Workload type to be managed by a database management system (DBMS) is a key consideration in tuning the DBMS. Allocations for resources, such as main memory, can be very different depending on whether the workload type is Online Transaction Processing (OLTP) or Decision Support System (DSS). The DBMS also experiences changes in workload type during the normal processing cycle of the DBMS. It would be preferable for the database administrators to recognize the significant shifts of workload type that demand reconfiguring the DBMS to maintain acceptable levels of performance. Disclosed is a workload type classifier module, used by a DBMS, for recognizing workload types so that the DBMS may then manage or adjust its performance and reconfigure its resources accordingly. The classifier may be constructed based on the most significant workload characteristics that differentiate OLTP from DSS. The classifier is then used for identifying changes in workload types contained in a workload.
摘要:
The present invention provides a method, system and program for optimizing compression of a workload processed by a database management system. In an embodiment of the present invention a method of optimizing the compression of database workloads is provided. Initially, an estimate of a cost of execution for each query according to a defined metric such as execution time or memory consumption is determined. A sub-set of queries is then selected from the workload in order of the most costly to least costly relative to the defined metric for compression according to either a predetermined compression threshold percentage or a threshold percentage derived from an allotted workload execution time. Compression is then performed on the selected sub-set of queries (i.e. those that will benefit the most from the compression) to achieve a net beneficial trade-off between the cost of workload compression and the cost of workload execution.